Soybeans and soybean products having low palmitic acid content

ABSTRACT

A method is described for producing soybean varieties and lines exhibiting low palmitic acid contents of less than about 6.0% of the total fatty acid composition down to no more than about 2.4% or lower. The novel soybean lines are obtained by crossing C1726 and A1973NMU-173 and by utilizing selected progeny from such crossing. Soybean lines having stearic acid contents of less than about 3.0%, down to about 1.5% and total saturated fatty acid contents less than about 7.0% down to no more than about 4.0% are also disclosed.

This is a continuation of application Ser. No. 08/180,112 filed 12 Jan.1994 (now abandoned), which is a continuation of Ser. No. 07/839,329filed 20 Feb. 1992 (now abandoned), which is a continuation-in-part ofSer. No. 07/461,361 filed 5 Jan. 1990 (now abandoned).

FIELD OF THE INVENTION

This invention relates to novel soybean seeds and products of soybeanseeds, such as soybean oil, and, more particularly, to soybean seeds andproducts containing a low level of saturated fatty acids, specificallylow levels of palmitic acid.

BACKGROUND OF THE INVENTION

Soybeans represent a significant world-wide food source, providing anexcellent source of protein. As such, soybeans represent a potentialalternative to meats.

Tofu and soymilk are two principal food products derived from soybeanseeds. More than one billion people in China and Southeast Asia, it hasbeen stated, rely on tofu as a major food protein source. (Proc. Int.Soya Protein Food Conf., American Soybean Assoc., p. 35, 1978). Soymilkis similarly an important source for food protein.

Soybean seeds also represent perhaps the most significant oilseed in theworld and contain significant nutritive properties. Soybean oil has thusbeen considered to be the major vegetable oil produced and consumed inthe United States, and more than 90% of this soybean oil is used in foodproducts (World Soybean Research Conference III Proceeding, Shibles, R.(Ed.), 1985).

Soybeans contain two different saturated fatty acids, viz.--palmiticacid (16:0) and stearic acid (18:0). Palmitic acid is generally themajor constituent, comprising some 70% of the total saturated fatty acidcontent.

The presence of the more typical level of palmitic acid may beconsidered undesirable for some applications. Extending back to the1950's, the medical community has emphasized the role of fat intake inthe pathogenesis of heart disease. The American Heart Association issueda series of reports dating from 1957 to the present; each reportemphasized alteration of the diet by reducing intake of saturated fats.The Association has continued to recommend such a reduction andcurrently suggests that saturated fats comprise no more than 10% of thetotal calories of an individual's intake.

This is particularly true of saturated fatty acids having a chain lengthof 12 to 16, which includes palmitic acid. There is some evidence thatstearic acid, having a chain length of 18, is less injurious or evenperhaps beneficial with respect to artery disease.

A major competitor of soybeans for the vegetable oil market is canola.Canola has been promoted as a healthier oil than soybean oil because ofits relatively lower saturated fatty acid content. It would be asignificant advance to be able to provide soybean oil which would have apalmitic acid content similar to that of canola.

The formidable nature of the task to provide a saturated acid content insoybeans similar to that in canola can be appreciated from a recentreport wherein it was stated that palmitic acid levels in soybean seedoil range from 9.3% to 17.4% within the world collection (Erickson etal., Journal of Heredity, 79, p. 465, 1988). The level of palmitic acidwould have to be reduced substantially below the reported minimum of9.3% to provide a palmitic acid content similar to that of canola. Thus,the palmitic acid content of canola would be expected to be below about6%; and applicants are aware of reported palmitic acid levels down toabout 4% or even slightly less.

The Erickson et al. article reports the inheritance of altered palmiticacid percentage in two soybean mutants, C1726 and C1727. The level ofpalmitic acid in C1726 averages 8.5%, and the range of values obtainedis set forth. The lines resulting from crossing the mutant line C1726with the commercial cultivar "Century" a re, also described.

It may also be desirable for some applications to develop a soybean linecharacterized by a low stearic acid content or a soybean linecharacterized by a low total saturated fatty acid content.

Despite the clear need for soybeans having a significantly reduced levelof palmitic acid, this objective still remains to be achieved.

SUMMARY OF THE INVENTION

It has been discovered that crossing two particular mutants, C1726 andA1937NMU-173, provides a population of soybean seeds exhibitingsignificantly reduced levels of palmitic acid. The palmitic acidconcentration obtained is less than about 6.0%, preferably less than5.5%, more preferably less than about 4.5%, and even more preferablyless than about 4.0% of the total fatty acid present. Palmitic acidcontents down to about 3.5% have been obtained.

In accordance with this invention, it has also been discovered thatutilizing selected progeny can provide soybean lines having palmiticacid contents of no more than about 2.5% or even less. Further, soybeanlines may be provided that are characterized by stearic acid contents ofless than about 3.0%, preferably no more than about 2.0%, and/or totalsaturated fatty acid contents of no more than about 7.0%, preferably nomore than about 5.0%, and, more preferably, no more than about 4.0%.

If desired, the soybeans of the present invention can be used as a donorparent in a backcrossing program with any desired commercial cultivar asa recurrent patent to isolate a variety having desirable seed yield andother agronomic characteristics, in addition to the reduced level ofpalmitic acid.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

The novel soybean seeds and plants of the present invention,characterized by reduced levels of palmitic acid, were obtained bycrossing mutant lines C1726 and Asgrow A1937NMU-173. C1726 is a mutantline developed and released by The United States Department ofAgriculture (Agricultural Research Service) and the Purdue UniversityAgricultural Experiment Station. According to the developers, the lineC1726 averages 8.5% palmitic acid and was originated as an M₂ plant froma population of Century soybean treated with ethyl methane sulfonate.

The line A1937NMU-173 was selected from the progeny of a populationdeveloped by treatment of seeds of the cultivar Asgrow A1937 withnitroso methyl urea (NMU). The mutation procedure utilized will bedescribed in detail hereinafter.

Crossing of the parent mutant lines C1726 and A1937NMU-173 to obtain thesoybean line of the present invention can be carried out by any desiredhybrid formation technique. Standard hybridization techniques are, ofcourse, well known and may be utilized. As an illustrative example,hybridization techniques are disclosed in Fehr, Principles of CultivarDevelopment, Vol. 1, Theory and Technique, Chapter 13, pp. 156-164,Macmillan Publishing Company, New York, 1987, which hybridizationtechniques are herein incorporated by reference.

Progeny from the crossing of C1726 and A1937NMU-173 include soybeanseeds wherein the palmitic acid content is less than 6.0% of the totalfatty acid composition, preferably less than about 5.5%, morepreferably, less than about 4.5%, and even more preferably less thanabout 4.0%. Surprisingly, soybean lines having as low as about 3.5%palmitic acid were obtained.

The fatty acid composition was determined by gas-liquid chromatographyusing the method as generally outlined in Graef et al. (Crop. Sci., 25:1076-1079, 1985). Thus, in general, the method comprises (1) crushingthe seed sample, (2) putting the crushed sample into a test tube with ahexane solvent and extracting the oil into the hexane, (3) the fattyacids in the oil are converted to their methyl esters using sodiummethoxide and methanol, (4) water is added to inactivate the sodiummethoxide catalyst, and (5) the methyl esters, which float to the top ofthe water layer, are diluted with hexane and become the sample that isintroduced into the column of the gas chromatography apparatus.

As may be appreciated, this general methodology may be employed andspecific aspects changed to lessen the time needed as desired. Forexample, the stationary phase selected for the columns will dictate thetemperature at which the sample can be introduced.

None of the specifics utilized, e.g.--capillary versus packed columns,are considered to affect to any appreciable extent the results obtainedfor an analysis. Rather, such specifics affect the time required forsample preparation and analysis.

The percentages of the fatty acids set forth herein, unless otherwisedesignated, thus are on a weight basis and refer to the percentage ofthe methyl ester of palmitic acid or other fatty acid compared to thetotal methyl esters of the fatty acid composition in the sample beinganalyzed. This can also be taken as the weight percentage of the fattyacid itself because the difference between the palmitic acid content andthat of its methyl ester as determined in the gas chromatographytechnique described herein is so minimal as may be ignored, as iscommonly done in this field.

The gas chromatography techniques described herein are routinely usedfor analysis of the fatty acid composition of soybeans. The experimentalerror is considered to be within the range of from about 1 to 5% or so,depending upon the magnitude of the peak. For example, with a relativelylarge peak indicative of an oleic acid content of 50% or so, theexperimental error may be as low as about 1% of the value,viz.--50±0.5%. At the other extreme, a small peak indicative of apalmitic acid content of 4.0% may have an experimental error of about5.0% of the value, viz.--4.0%±0.2.

As may be appreciated, the palmitic acid levels of the soybeans of thepresent invention set forth herein were obtained from soybeans grown inIowa and Puerto Rico. Growth under climatic conditions cooler or warmermay result in a somewhat altered fatty acid composition. However, whilethe specific results may vary somewhat depending upon the specificgrowing conditions experienced, the progeny of the present inventionwill be characterized by extremely low palmitic acid contents relativeto other soybean lines grown under similar conditions.

Progeny exhibiting the desired low palmitic acid trait can be crossedwith other progeny to provide a population of soybean seeds havingextremely low palmitic acid contents. It is theoretically possible thatthe methodology disclosed in the present invention may be utilized toyield soybean seeds, products and oil with down to zero palmitic acid.It can be expected that crosses utilizing the more desirable progenyshould be capable of providing lines having palmitic acid contents downto about 3.0% or 2.5%, or even down to about 2.0% or so.

Indeed, in accordance with the present invention, crosses utilizing themore desirable progeny have already provided soybean lines characterizedby palmitic acid contents down to 2.4%. As will be described in theExamples, crossing of progeny from the crossing of C1726 andA1937NMU-173 with the commercial cultivar Kenwood result in soybeanlines having such extremely low palmitic acid contents.

Pursuant to a further aspect of this invention, soybean lines areprovided that are characterized by stearic acid contents of less than3.0%, preferably less than 2.0%, and, more preferably, no more thanabout 1.5%. Additionally, soybean lines are provided that have totalsaturated fatty acid contents of less than 7.0%, preferably less than5.0%, and, more preferably, no more than about 4.0%.

These low stearic acid content and/or low total saturated fatty acidcontent soybean lines may likewise be obtained by using selected progenyfrom the low palmitic acid soybean lines disclosed herein. To this end,such low stearic acid content and/or low total saturated fatty acidcontent soybean lines can be obtained by crossing the commercialcultivar Kenwood with selected progeny from the crossing of C1726 andA1937NMU-173. A particularly desirable progeny in this respect isAX5152-105.

It can be expected the crosses utilizing the more desirable progenyshould be capable of providing soybean lines having stearic acidcontents down to about 1.0% or so. Similarly, utilizing the moredesirable progeny should be capable of providing soybean lines havingtotal saturated fatty acid contents down to about 3.0% or so.

Further, progeny can be crossed, if desired, with other progeny, or withany other soybean line or cultivar to yield a soybean cultivar havingthe desired seed yield or other desired agronomic traits as well as thedesired low palmitic acid trait. Self-pollination of selected progenymay likewise yield lines having characteristics desired for someapplications.

Any hybridization technique may be used, and many are known as has beendescribed herein. For example, the selection of progeny having thedesired low palmitic acid trait can be obtained by conducting recurringbackcrossing with a commercial variety until a desirable variety hasbeen isolated. Backcrossing techniques are known, as disclosed in Fehr,Principles of Cultivar Development, Vol. 1, Theory and Technique,Chapter 28, pp. 360-376, the disclosure of which is herein incorporatedby reference.

As one example, backcrossing using the desired F₂ seeds obtained bynatural self-pollination of the F₁ plants could be carried out asfollows:

(1) Plant F₁ seeds obtained by crossing a parent with the desired lowpalmitic acid trait to the desired commercial cultivar (recurrentparent). Sample F₂ seeds from F₁ plants are analyzed for fatty acidconcentration, and seeds with the desired low palmitic acid content areplanted for backcrossing.

(2) Cross-pollinate the desired commercial cultivar (recurrent parent)with an F₂ plant having the low palmitic acid content.

(3) Plant the BC₁ F₁ seeds and obtain BC₁ F₂ seeds by naturalself-pollination. Sample BC₁ F₂ seeds are analyzed for fatty acidconcentration, and those displaying the low palmitic acid trait arebackcrossed to the recurrent parent.

(4) The backcross and selection procedure herein described (Step 3) canbe repeated until lines with the desired low palmitic acid compositionand agronomic performance are recovered. It is believed that four ofthese backcross cycles should serve to transfer the low palmitic acidtrait to the desired cultivar (viz.--recurrent parent), although thenumber of such cycles can be fewer, or more, as is desired. The resultis the production of a soybean line quite similar to the commercialcultivar except having the desired low palmitic acid content.

Any commercial cultivar (recurrent parent) desired may be employed forbackcrossing. Factors such as, for example, seed yield, geographicalarea, and many others, as is known, will generally dictate the cultivarselected from the several hundred commercial cultivars available.

The following Examples are illustrative, but not in limitation, of thepresent invention. The gas chromatography results obtained from theinstrument itself are reported to two decimal points (i.e.--"0.00"). Asreported herein, the fatty acid values are set forth to one decimalpoint. Values of 6 or more in the second decimal point were raised(e.g.--4.29 is reported herein as 4.3), values of 4 or less are ignored(e.g.--4.24 is reported as 4.2), values of 5 are raised if the firstdecimal is odd (e.g.--4.15 is reported as 4.2) and ignored if even(e.g.--4.25 is reported as 4.2).

EXAMPLE 1

This Example describes the preparation of the mutant line A1937NMU-173.

Mutant line A1937NMU-173 was obtained from nitroso methyl urea (NMU)treatment of the parent variety Asgrow A1937. In May, 1985, 2,500 seedsof A1937 were soaked in 2.5 L distilled water in a 6 L flask for 9 hoursat room temperature. The flask was aerated for the 9 hours of soaking.The water was drained from the flask, and 2.5 L of 2.5 mM NMU in 0.1molar phosphate buffer at pH 5.5 were added. The seeds were soaked withaeration for 3 hours, the solution was drained and the seeds were rinsedtwice with distilled water. Treated seeds were placed in plastic bags toprevent drying and transported to the Agricultural Engineering andAgronomy Research Center near Ames, Iowa. The seeds were planted 2.5 cmdeep in moist soil within 4 hours after the last rinse. The soil waswatered regularly to keep it moist until seeding emergence. Theproperties of the mutant seed and their progeny were evaluated beginningwith the M₄ generation.

A similar number of seeds was harvested from each of the M₁ (firstmutant generation) plants in the population to obtain 2,000 M₂ seeds. Arandom sample of 1,000 of the second generation M₂ seeds from thepopulation was planted in October at the Iowa StateUniversity-University of Puerto Rico soybean nursery at Isabela, PuertoRico. About 2,000 M₃ seeds were obtained by harvesting a similar numberof seeds from each M₂ plant. In February, 1,000 M₃ seeds were planted inPuerto Rico. About 2,000 M₄ seeds were obtained by harvesting a similarnumber of seeds from each M₃ plant. In May, 1,000 M₄ seeds were plantedat Ames. Five hundred M₄ plants were harvested individually from thepopulation, and a 10-seed sample from selected plants was analyzed bygas-liquid chromatography to determine the fatty acid composition. M₅progeny of selected plants were planted in Puerto Rico in November,1987; and the results confirmed the unique fatty acid composition of theM₄ parent plant.

Table I sets forth the analysis of the fatty acid composition of a10-seed sample from the M₄ plant from which A1937NMU-173 originated aswell as that of its parent:

                  TABLE I                                                         ______________________________________                                                Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                             Linolenic                             Seed      Acid     Acid    Acid  Acid   Acid                                  Identification                                                                          (16:0)   (18:0)  (18:1)                                                                              (18:2) (18:3)                                ______________________________________                                        A1937NMU-173                                                                            6.8      2.8     19.7  61.4   9.3                                   A1937 parent                                                                            12.3     3.8     18.7  57.2   8.0                                   ______________________________________                                    

Table II sets forth the analysis of M₅ progeny from the M₄ plantA1937NMU-173 as well as that of A5, a line with a palmitic acid contentconsidered to be typical of commercial soybean varieties:

                  TABLE II                                                        ______________________________________                                                Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                             Linolenic                             Seed      Acid     Acid    Acid  Acid   Acid                                  Identification                                                                          (16:0)   (18:0)  (18:1)                                                                              (18:2) (18:3)                                ______________________________________                                        A1937NMU-173                                                                            7.2      3.6     21.3  59.2   8.7                                   A5        10.5     3.9     29.6  51.7   4.3                                   ______________________________________                                    

EXAMPLE 2

This Example describes the crossing of C1726 and A1937NMU-173 to obtainthe soybean lines of the present invention characterized by low palmiticacid contents.

Reciprocal crosses were made between C1726 and A1937NMU-173 at theAgricultural Engineering and Agronomy Research Center near Ames, Iowa,during the summer of 1988. The hybrid F₁ seeds obtained from the crosswere designated AX5152.

The F₁ and parent seeds were split so that the embryo was left intact.The non-embryo portion (approximately one-third of the seed) wasanalyzed for fatty acid composition. The seed portion containing theembryo of each F₁ and parent seed was planted in the Iowa StateUniversity-University of Puerto Rico nursery at Isabela, Puerto Rico, inOctober, 1988. F₂ seeds were obtained by natural self-pollination. EachF₁ and parent plant was harvested individually.

Ten F₂ seeds from each of the F₁ plants designated AX5152-7, AX5152-34,AX5152-105, AX5152-115, and AX5152-123 were split; and the nonembryoportion of the F₂ seeds was analyzed for fatty acid composition by gaschromatography. The embryo portion of each of these seeds was planted atthe Agronomy Research Center near Ames, Iowa, in May, 1989. Elevenindividual F3 seeds were analyzed from each F₂ plant.

Table III summarizes the analysis of the fatty acid composition of theF₂ seeds from Puerto Rico having the desired low palmitic acid contentand that of the parent lines:

                  TABLE III                                                       ______________________________________                                                Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                             Linolenic                             Seed      Acid     Acid    Acid  Acid   Acid                                  Identification                                                                          (16:0)   (18:0)  (18:1)                                                                              (18:2) (18:3)                                ______________________________________                                        C1726 Parent.sup.1                                                                      8.2      3.8     21.5  58.6   7.9                                   A1937NMU-173                                                                            7.8      4.4     19.4  59.8   8.5                                   Parent.sup.2                                                                  AX5152-7  4.3      4.3     24.8  59.1   7.4                                   AX5152-34 4.8      3.5     21.2  61.6   8.9                                   AX5152-105                                                                              5.5      3.1     19.7  63.2   8.5                                   AX5152-115                                                                              3.6      3.4     24.4  62.0   6.6                                   AX5152-123                                                                              4.4      3.5     21.0  63.0   8.1                                   ______________________________________                                         .sup.1 Average of 9 seeds, palmitic acid contents ranged from 8.0 to 8.3%     among the individual seeds.                                                   .sup.2 Average of 10 seeds, palmitic acid contents ranged from 7.4 to 8.3     among the individual seeds                                               

Table VI summarizes the analysis of the fatty acid composition of the F₃progeny from the F₂ plants as well as that of the parents:

                  TABLE IV                                                        ______________________________________                                                Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                             Linolenic                             Seed      Acid     Acid    Acid  Acid   Acid                                  Identification                                                                          (16:0)   (18:0)  (18:1)                                                                              (18:2) (18:3)                                ______________________________________                                        C1726 Parent                                                                            8.1      3.4     25.2  55.1   8.3                                   A1937NMU-173                                                                            6.9      3.8     28.1  53.8   7.4                                   Parent                                                                        AX5152-7  4.2      3.3     24.7  59.7   8.0                                   AX5152-34 4.6      3.0     31.4  53.5   7.4                                   AX5152-105                                                                              4.6      2.7     22.3  61.0   9.4                                   AX5152-115                                                                              4.2      3.4     25.7  59.3   7.3                                   AX5152-123                                                                              4.4      2.7     39.3  47.4   6.2                                   ______________________________________                                    

EXAMPLE 3

This Example describes the crossing of AX5152-105, obtained as describedin Example 2, with the commercial cultivar Kenwood to obtain soybeanlines of the present invention characterized by low stearic acid and lowtotal saturated fatty acid contents.

Crosses were made between the cultivar Kenwood and AX5152-105 at theIowa State University-University of Puerto Rico nursery during March1990. The hybrid F₁ seeds obtained from the cross were designatedAX7343.

F₁ plants of the cross AX7343 were grown at the Agricultural Engineeringand Agronomy Research Center near Ames, Iowa, during the summer of 1990.F₂ seeds were obtained by natural self-pollination. A total of 1,000 F₂seeds from the cross were planted in November, 1990, in the Iowa StateUniversity-University of Puerto Rico nursery at Isabela, Puerto Rico. F₃seeds were obtained by natural self-pollination. Three seeds wereharvested from each F₂ plant to obtain a bulk sample of F₃ seeds fromthe population. A random sample of 870 F₃ seeds was planted in PuertoRico in February, 1991. F₄ seeds were obtained by naturalself-pollination. Three F₄ seeds were harvested from each F₃ plant toobtain a bulk sample of F₄ seeds from the population. In May, 1991, arandom sample of the 1050 F₄ seeds was planted at the AgriculturalEngineering and Agronomy Research Center near Ames, Iowa. Approximately845 F₄ plants were harvested individually, and a 10-seed sample fromeach plant was analyzed by gas-liquid chromatography to determine fattyacid composition.

Table V sets forth the fatty acid composition of the F₄ plantcharacterized by a low palmitic acid content, a low stearic acid contentand a low total saturated fatty acid content, as well as the fatty acidcomposition of the parent lines:

                  TABLE V                                                         ______________________________________                                                Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                             Linolenic                             Seed      Acid     Acid    Acid  Acid   Acid                                  Identification                                                                          (16:0)   (18:0)  (18:1)                                                                              (18:2) (18:3)                                ______________________________________                                        AX7343-25 2.5      1.9     24.9  57.9   12.8                                  Kenwood   12.1     4.3     21.3  55.2   7.1                                   AX5152-105                                                                              3.7      3.1     19.8  64.5   9.0                                   ______________________________________                                    

Twenty-four F₅ seeds of the plant AX7343-25 were split so that theembryonic axis was left intact. The portion of each seed without theembryonic axis (approximately one-third of the seed) was analyzed forfatty acid composition by gas chromatography.

Table VI sets forth the fatty acid composition of individual F₅ seedscharacterized by the lowest palmitic acid content, lowest stearic acidcontent, and the lowest total saturated fatty acid content ever reportedfor soybeans as far as applicants are aware, as well as the fatty acidcompositions of the parent lines:

                  TABLE VI                                                        ______________________________________                                                Fatty Acid Composition                                                          Palmitic Stearic Oleic Linoleic                                                                             Linolenic                             Seed      Acid     Acid    Acid  Acid   Acid                                  Identification                                                                          (16:0)   (18:0)  (18:1)                                                                              (18:2) (18:3)                                ______________________________________                                        AX7343-25-19                                                                            2.4      1.8     24.2  59.8   11.8                                  AX7343-25-23                                                                            2.5      1.5     24.1  58.3   13.6                                  Kenwood   12.5     4.3     22.4  53.6   7.2                                   AX5152-105                                                                              3.9      3.2     21.8  62.7   8.4                                   ______________________________________                                    

2,500 seeds of A1937NMU-173 were deposited on Jan. 26, 1996 under theBudapest Treaty in the American Type Culture Collection (ATCC) at 12301Parklawn Drive, Rockville, Md. 20852, U.S.A., and have been assignedATCC Accession No. 97429. Additionally, 2,500 seeds of C1726 have beendeposited under the Budapest Treaty at the same depository on the samedate and have been assigned ATCC Accession No. 97430.

Although the foregoing invention has been described in detail withexamples for purposes of understanding the invention, it will beunderstood by those skilled in the art that various modifications of theinvention may be practiced while remaining within the spirit and thescope of the appended claims.

What is claimed is:
 1. A method for producing a soybean plant thatyields mature seed having a reduced endogenous palmitic acid contentcomprising:(a) crossing a first soybean parent plant that is C1726having ATCC Accession No. 97430, with a second soybean parent plant thatis A1937NMU-173 having ATCC Accession No. 97429; (b) obtaining hybridsoybean seeds from the cross and germinating said seeds to producesegregating populations of soybean plants that are allowed toself-pollinate; and (c) selecting a plant of step (b) that yields matureseed following self pollination having an endogenous palmitic acidcontent in the oil thereof in an amount lower than the palmitic acid ofthe parent plant of step (a) having the lower endogenous palmitic acidcontent when the parent plants and the offspring of the cross are grownunder the same conditions.
 2. A method according to claim 1 wherein saidsoybean plant that is selected in step (c) contains an endogenouspalmitic acid content in the oil of the mature seed formed thereon ofless than about 6% by weight as determined by gas chromatography.
 3. Amethod according to claim 1 wherein said soybean plant that is selectedin step (c) contains an endogenous palmitic acid content in the oil ofthe mature seed formed thereon of less than about 5.5% by weight asdetermined by gas chromatography.
 4. A method according to claim 1wherein said soybean plant that is selected in step (c) contains anendogenous palmitic acid content in the oil of the mature seed formedthereon of less than about 4.5% by weight as determined by gaschromatography.
 5. A method according to claim 1 wherein said soybeanplant that is selected in step (c) contains an endogenous palmitic acidcontent in the oil of the mature seed formed thereon of less than about4% by weight as determined by gas chromatography.
 6. A method accordingto claim 1 wherein said soybean plant that is selected in step (c)contains an endogenous palmitic acid content in the oil of the matureseed formed thereon from about 2.4% to about 5.5% by weight asdetermined by gas chromatography.
 7. A soybean plant which upon selfpollination yields mature seed that exhibits a reduced palmitic acidcontent and is the product of crossing a first soybean parent that isC1726 having ATCC Accession No. 97430, with a second soybean parent thatis A1937NMU-173 having ATCC Accession No. 97429, and wherein the soybeanplant resulting from said cross yields mature seed that provides anendogenous oil comprising palmitic acid in an amount lower than theendogenous palmitic acid content of the parent having the lower palmiticacid content when the parent plants and the offspring of said cross aregrown under the same conditions.
 8. A mature soybean seed formed by theself pollination of the soybean plant according to claim 7, and thedescendants thereof that retain said reduced palmitic acid content whengrown under the same conditions.
 9. A mature soybean seed formed by theself pollination of the plant selected in step (c) of the method ofclaim 1 and descendants thereof which upon self pollination forms matureseeds that retain said reduced palmitic acid content when grown underthe same conditions.
 10. A mature soybean seed according to claim 8 thatcontains an endogenous palmitic acid content of less than about 6% byweight as determined by gas chromatography.
 11. A mature soybean seedaccording to claim 8 that contains an endogenous palmitic acid contentof less than about 5.5% by weight as determined by gas chromatography.12. A mature soybean seed according to claim 8 that contains anendogenous palmitic acid content of less than about 4.5% by weight asdetermined by gas chromatography.
 13. A mature soybean seed according toclaim 8 that contains an endogenous palmitic acid content of less thanabout 4% by weight as determined by gas chromatography.
 14. A maturesoybean seed according to claim 8 that contains an endogenous palmiticacid content from about 2.4% to about 5.5% by weight as determined bygas chromatography.